[Diagnostic values of serum type III procollagen N-terminal peptide in type IV gastric cancer].

Since increased synthesis of collagen has been demonstrated in tissue of type IV gastric cancer, we attempted to distinguish type IV gastric cancer from other cancers by measuring serum levels of type III procollagen N-terminal peptide (type III-N-peptide). Mean serum levels in type IV gastric cancer patients without metastasis were found to be elevated above normal values and developed a tendency to be higher than those in types I, II and III gastric cancer patients without metastasis. Highly positive ratios were found in patients with liver diseases including hepatoma and colon cancer, biliary tract cancer, and esophageal cancer patients with liver, lung or bone metastasis, but only 2 out of 14 of these cancer patients without such metastasis showed positive serum levels of type III-N-peptide. Positive cases in patients with type IV gastric cancer were obtained not only in the group with clinical stage IV but also in the groups with clinical stages II and III. In addition, high serum levels of type III-N-peptide in patients with type IV gastric cancer were seen not only in the cases with liver, lung or bone metastasis but also in cases with disseminated peritoneal metastasis alone. These results suggest that if the serum level of type III-N-peptide is elevated above normal values, type IV gastric cancer should be suspected after ruling out liver diseases, myelofibrosis and liver, lung or bone metastasis.